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    DN 50 - DN 900 (2” - 36”)
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    Engineered for abrasive slurry processes

Knife gate valves SLV and SLF

Stafsjö’s knife gate valves SLV and SLF are particularly suitable for abrasive and demanding slurry where operation reliability and low life cycle cost are emphasized. The SLV is a lugged version while the SLF is fully flanged and especially suitable on old non-centred pipes or low pressure applications. 

When the valves are in opened position, the seats form a tight extension of the pipe line and no metal parts are in contact with the media. When the valve closes the two seats are displaced axially forming a seal with the gate until it forms a complete closure – 100% tight in any pressure direction.

The SLV and SLF comes with a coated valve body in nodular iron with integrated purge ports in the lower end to be utilized if a bottom cover is assembled on the valve. The unique seats are available in low friction special EPDM, natural rubber or Viton. These seal against a gate specially machined and grinded to reduce the friction when the valve is operated. The gate can also be hard chromed to give a really hard and wear resistant surface.

The SLV valve is available from DN 50/2" up to DN 900/36" and the SLF from DN 80 up to DN 400 (3" to 16"). Larger sizes on request. Further information on the valves is available in the product data sheets.

Other slurry valves are the high pressure versions SLH and SLX which can be supplied for pressures up to 50 bar (720 psi). 


A precise gate guidance extend the valve’s service life

A solid top works (1), a robust gland box system (2), precisely machined gate supports (3) is crucial during operation to keep the gate in position and to minimize the wear on the seats. The extended face-to-face (4) further reduce the stress on the seats.

Built in steel reinforcements improve the performance

The front reinforcement rings (4) ensure the seats shape, position and strength remain during operation while the flange sealing reinforcements (5) secure a tight and exact position of the seats towards the connecting flanges. 

Integrated expansion areas give low operating force and minimize the stress on the seats

The seat entrance area (6) is designed to give a smooth gate entry and the expansion area (7) allows the seat to be axially flexible requiring minimal operating force. 

Contact us if you have any questions